1. Paying full price for meat. "Meat is usually the most expensive item on your dinner plate," d'Arabian says. She suggests checking circulars for "loss leaders"—highly discounted items that get shoppers into stores. Often, cuts of pork, beef, and chicken will be 50 to 75% off. Buy this meat in bulk then freeze it for later.

2. Being a slave to a recipe. Instead of buying every item on a long recipe list, think about ingredients you already have and could swap in. "Lemon juice is an acid, so try using another acid, such as vinegar or orange juice in its place," d'Arabian told us. "Soft leafy herbs such a cilantro, mint, basil and parsley, are often interchangeable."

3. Not using the freezer. You can save a lot of money by freezing bread, bacon, herbs (d'Arabian freezes fresh herbs with oil in ice-cube trays), and tomatoes. Buy these items in bulk when they're on sale, and you'll save even more.

4. Thinking that "inexpensive" ingredients don't warrant budget shopping. Yeah, a can of beans is pretty cheap. But d'Arabian points out that you can buy five cans' worth of dried beans for the price of one can. Check out her blog post for how to portion out and cook your own.

5. Not doing math in the produce aisle. Most produce items are available pre-packaged or loose. "Take 10 seconds to do some quick math to determine the per-pound price of a package before deciding whether to buy loose or packaged," d'Arabian says. Usually, potatoes and carrots are cheaper packaged, while mushrooms, apples, and oranges are cheaper by themselves.

6. Grabbing a big cart. "Studies have shown that grocery stores can do one simple thing that will result in you unwittingly spending more money: put out bigger grocery carts!" d'Arabian says. "Use this information to your advantage and always select the smallest cart available." If the store only has carts, fill up yours with less expensive products like produce before hitting the snack aisles. Melissa d'Arabian's New York Times best-selling cookbook, "Ten Dollar Dinners: 140 Recipes and Tips to Elevate Simple, Fresh Meals Any Night of the Week."Courtesy Melissa d'Arabian

7. Splurging in the wrong department. Replacing rib-eye steak with filet mignon can cost you an extra $15 per pound, d'Arabian says. Instead, treat yourself in the produce aisle. Expensive wild mushrooms or heirloom tomatoes cost $1 or $2 more, but will make your meal a lot nicer.

8. Overlooking the salad bar. "A handful of hazelnuts from that aisle will set you back only 20 or 30 cents—toast, chop, and sprinkle over green beans or in an inexpensive lettuce salad and you have a fancy restaurant-worthy dish," d'Arabian says. "The salad bar is also a great way to grab a small quantity of a high-impact ingredient (such as high-quality briny olives for a tapenade)."

9. Not asking the grocery staff for help. "Ask the person behind the butcher counter for advice on how to cook an unfamiliar cut of meat that is on sale, or ask if he will break down a large inexpensive pork loin into a variety of cuts: chops, cubes, and a few smaller roasts," d'Arabian recommends.

10. Getting bogged down by a list. "Be open to guidance from the sales prices," d'Arabian shares. "I usually just write 'vegetables for dinner' on my list, and let the prices be my guide when I'm in the produce aisle."

11. Not knowing the prices of the things you buy most. In order to shop smarter, you need to know how much essential items like chicken breasts, milk, or diapers cost normally. That will help you spot a bargain at the store. Make a list of the items you buy most so you can stock up when there's a sale.

12. Thinking that saving only happens at the store. "Ask any restaurateur: Half the battle in saving money is in inventory management. Manage your pantry and ingredients wisely, and you will save money!" d'Arabian says. "Also important: managing your leftovers. Remember, the most expensive ingredient in your kitchen right now is the one you throw away."